Commit | Line | Data |
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953192ba MD |
1 | /* |
2 | * filter-visitor-generate-bytecode.c | |
3 | * | |
4 | * LTTng filter bytecode generation | |
5 | * | |
6 | * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
8 | * This library is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU Lesser General Public License, version 2.1 only, | |
10 | * as published by the Free Software Foundation. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public License | |
18 | * along with this library; if not, write to the Free Software Foundation, | |
19 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include <errno.h> | |
46820c8b MD |
25 | #include <common/align.h> |
26 | ||
953192ba MD |
27 | #include "filter-bytecode.h" |
28 | #include "filter-ir.h" | |
29 | #include "filter-ast.h" | |
30 | ||
a187da1a DG |
31 | #include <common/macros.h> |
32 | ||
953192ba MD |
33 | #ifndef max_t |
34 | #define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b))) | |
35 | #endif | |
36 | ||
37 | //#define INIT_ALLOC_SIZE PAGE_SIZE | |
38 | #define INIT_ALLOC_SIZE 4 | |
39 | ||
40 | static | |
41 | int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx, | |
42 | struct ir_op *node); | |
43 | ||
01a204f0 CB |
44 | static inline int fls(unsigned int x) |
45 | { | |
46 | int r = 32; | |
47 | ||
48 | if (!x) | |
49 | return 0; | |
50 | if (!(x & 0xFFFF0000U)) { | |
51 | x <<= 16; | |
52 | r -= 16; | |
53 | } | |
54 | if (!(x & 0xFF000000U)) { | |
55 | x <<= 8; | |
56 | r -= 8; | |
57 | } | |
58 | if (!(x & 0xF0000000U)) { | |
59 | x <<= 4; | |
60 | r -= 4; | |
61 | } | |
62 | if (!(x & 0xC0000000U)) { | |
63 | x <<= 2; | |
64 | r -= 2; | |
65 | } | |
66 | if (!(x & 0x80000000U)) { | |
67 | x <<= 1; | |
68 | r -= 1; | |
69 | } | |
70 | return r; | |
71 | } | |
72 | ||
73 | static inline int get_count_order(unsigned int count) | |
74 | { | |
75 | int order; | |
76 | ||
77 | order = fls(count) - 1; | |
78 | if (count & (count - 1)) | |
79 | order++; | |
80 | return order; | |
81 | } | |
82 | ||
953192ba | 83 | static |
53a80697 | 84 | int bytecode_init(struct lttng_filter_bytecode_alloc **fb) |
953192ba | 85 | { |
1029587a MD |
86 | uint32_t alloc_len; |
87 | ||
88 | alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + INIT_ALLOC_SIZE; | |
89 | *fb = calloc(alloc_len, 1); | |
953192ba MD |
90 | if (!*fb) { |
91 | return -ENOMEM; | |
92 | } else { | |
1029587a | 93 | (*fb)->alloc_len = alloc_len; |
953192ba MD |
94 | return 0; |
95 | } | |
96 | } | |
97 | ||
98 | static | |
53a80697 | 99 | int32_t bytecode_reserve(struct lttng_filter_bytecode_alloc **fb, uint32_t align, uint32_t len) |
953192ba MD |
100 | { |
101 | int32_t ret; | |
102 | uint32_t padding = offset_align((*fb)->b.len, align); | |
ec96a8f6 | 103 | uint32_t new_len = (*fb)->b.len + padding + len; |
1029587a | 104 | uint32_t new_alloc_len = sizeof(struct lttng_filter_bytecode_alloc) + new_len; |
ec96a8f6 | 105 | uint32_t old_alloc_len = (*fb)->alloc_len; |
953192ba | 106 | |
ec96a8f6 | 107 | if (new_len > LTTNG_FILTER_MAX_LEN) |
5ddb0a08 CB |
108 | return -EINVAL; |
109 | ||
ec96a8f6 | 110 | if (new_alloc_len > old_alloc_len) { |
d0b96690 DG |
111 | struct lttng_filter_bytecode_alloc *newptr; |
112 | ||
ec96a8f6 MD |
113 | new_alloc_len = |
114 | max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1); | |
d0b96690 DG |
115 | newptr = realloc(*fb, new_alloc_len); |
116 | if (!newptr) | |
953192ba | 117 | return -ENOMEM; |
d0b96690 | 118 | *fb = newptr; |
1029587a | 119 | /* We zero directly the memory from start of allocation. */ |
ec96a8f6 MD |
120 | memset(&((char *) *fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len); |
121 | (*fb)->alloc_len = new_alloc_len; | |
953192ba MD |
122 | } |
123 | (*fb)->b.len += padding; | |
124 | ret = (*fb)->b.len; | |
125 | (*fb)->b.len += len; | |
126 | return ret; | |
127 | } | |
128 | ||
129 | static | |
53a80697 | 130 | int bytecode_push(struct lttng_filter_bytecode_alloc **fb, const void *data, |
953192ba MD |
131 | uint32_t align, uint32_t len) |
132 | { | |
133 | int32_t offset; | |
134 | ||
135 | offset = bytecode_reserve(fb, align, len); | |
136 | if (offset < 0) | |
137 | return offset; | |
138 | memcpy(&(*fb)->b.data[offset], data, len); | |
139 | return 0; | |
140 | } | |
141 | ||
142 | static | |
53a80697 | 143 | int bytecode_push_logical(struct lttng_filter_bytecode_alloc **fb, |
953192ba MD |
144 | struct logical_op *data, |
145 | uint32_t align, uint32_t len, | |
146 | uint16_t *skip_offset) | |
147 | { | |
148 | int32_t offset; | |
149 | ||
150 | offset = bytecode_reserve(fb, align, len); | |
151 | if (offset < 0) | |
152 | return offset; | |
153 | memcpy(&(*fb)->b.data[offset], data, len); | |
154 | *skip_offset = | |
155 | (void *) &((struct logical_op *) &(*fb)->b.data[offset])->skip_offset | |
156 | - (void *) &(*fb)->b.data[0]; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | static | |
53a80697 | 161 | int bytecode_patch(struct lttng_filter_bytecode_alloc **fb, |
953192ba MD |
162 | const void *data, |
163 | uint16_t offset, | |
164 | uint32_t len) | |
165 | { | |
166 | if (offset >= (*fb)->b.len) { | |
167 | return -EINVAL; | |
168 | } | |
169 | memcpy(&(*fb)->b.data[offset], data, len); | |
170 | return 0; | |
171 | } | |
172 | ||
173 | static | |
174 | int visit_node_root(struct filter_parser_ctx *ctx, struct ir_op *node) | |
175 | { | |
176 | int ret; | |
177 | struct return_op insn; | |
178 | ||
179 | /* Visit child */ | |
180 | ret = recursive_visit_gen_bytecode(ctx, node->u.root.child); | |
181 | if (ret) | |
182 | return ret; | |
183 | ||
184 | /* Generate end of bytecode instruction */ | |
185 | insn.op = FILTER_OP_RETURN; | |
186 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); | |
187 | } | |
188 | ||
953192ba MD |
189 | static |
190 | int visit_node_load(struct filter_parser_ctx *ctx, struct ir_op *node) | |
191 | { | |
192 | int ret; | |
193 | ||
194 | switch (node->data_type) { | |
195 | case IR_DATA_UNKNOWN: | |
196 | default: | |
197 | fprintf(stderr, "[error] Unknown data type in %s\n", | |
198 | __func__); | |
199 | return -EINVAL; | |
200 | ||
201 | case IR_DATA_STRING: | |
202 | { | |
203 | struct load_op *insn; | |
204 | uint32_t insn_len = sizeof(struct load_op) | |
205 | + strlen(node->u.load.u.string) + 1; | |
206 | ||
207 | insn = calloc(insn_len, 1); | |
208 | if (!insn) | |
209 | return -ENOMEM; | |
210 | insn->op = FILTER_OP_LOAD_STRING; | |
953192ba MD |
211 | strcpy(insn->data, node->u.load.u.string); |
212 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); | |
213 | free(insn); | |
214 | return ret; | |
215 | } | |
216 | case IR_DATA_NUMERIC: | |
217 | { | |
218 | struct load_op *insn; | |
219 | uint32_t insn_len = sizeof(struct load_op) | |
220 | + sizeof(struct literal_numeric); | |
221 | ||
222 | insn = calloc(insn_len, 1); | |
223 | if (!insn) | |
224 | return -ENOMEM; | |
225 | insn->op = FILTER_OP_LOAD_S64; | |
58d494e4 | 226 | memcpy(insn->data, &node->u.load.u.num, sizeof(int64_t)); |
953192ba MD |
227 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
228 | free(insn); | |
229 | return ret; | |
230 | } | |
e90d8561 MD |
231 | case IR_DATA_FLOAT: |
232 | { | |
233 | struct load_op *insn; | |
234 | uint32_t insn_len = sizeof(struct load_op) | |
235 | + sizeof(struct literal_double); | |
236 | ||
237 | insn = calloc(insn_len, 1); | |
238 | if (!insn) | |
239 | return -ENOMEM; | |
240 | insn->op = FILTER_OP_LOAD_DOUBLE; | |
58d494e4 | 241 | memcpy(insn->data, &node->u.load.u.flt, sizeof(double)); |
e90d8561 MD |
242 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
243 | free(insn); | |
244 | return ret; | |
245 | } | |
586dc72f MD |
246 | case IR_DATA_FIELD_REF: /* fall-through */ |
247 | case IR_DATA_GET_CONTEXT_REF: | |
953192ba MD |
248 | { |
249 | struct load_op *insn; | |
250 | uint32_t insn_len = sizeof(struct load_op) | |
251 | + sizeof(struct field_ref); | |
252 | struct field_ref ref_offset; | |
ec96a8f6 MD |
253 | uint32_t reloc_offset_u32; |
254 | uint16_t reloc_offset; | |
953192ba MD |
255 | |
256 | insn = calloc(insn_len, 1); | |
257 | if (!insn) | |
258 | return -ENOMEM; | |
586dc72f MD |
259 | switch(node->data_type) { |
260 | case IR_DATA_FIELD_REF: | |
261 | insn->op = FILTER_OP_LOAD_FIELD_REF; | |
262 | break; | |
263 | case IR_DATA_GET_CONTEXT_REF: | |
264 | insn->op = FILTER_OP_GET_CONTEXT_REF; | |
265 | break; | |
266 | default: | |
3a68137c | 267 | free(insn); |
586dc72f MD |
268 | return -EINVAL; |
269 | } | |
953192ba MD |
270 | ref_offset.offset = (uint16_t) -1U; |
271 | memcpy(insn->data, &ref_offset, sizeof(ref_offset)); | |
65775683 | 272 | /* reloc_offset points to struct load_op */ |
ec96a8f6 MD |
273 | reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b); |
274 | if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) { | |
275 | free(insn); | |
276 | return -EINVAL; | |
277 | } | |
278 | reloc_offset = (uint16_t) reloc_offset_u32; | |
953192ba MD |
279 | ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len); |
280 | if (ret) { | |
281 | free(insn); | |
282 | return ret; | |
283 | } | |
284 | /* append reloc */ | |
285 | ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset, | |
286 | 1, sizeof(reloc_offset)); | |
287 | if (ret) { | |
288 | free(insn); | |
289 | return ret; | |
290 | } | |
291 | ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref, | |
292 | 1, strlen(node->u.load.u.ref) + 1); | |
293 | free(insn); | |
294 | return ret; | |
295 | } | |
296 | } | |
297 | } | |
298 | ||
299 | static | |
300 | int visit_node_unary(struct filter_parser_ctx *ctx, struct ir_op *node) | |
301 | { | |
302 | int ret; | |
303 | struct unary_op insn; | |
304 | ||
305 | /* Visit child */ | |
306 | ret = recursive_visit_gen_bytecode(ctx, node->u.unary.child); | |
307 | if (ret) | |
308 | return ret; | |
309 | ||
310 | /* Generate end of bytecode instruction */ | |
311 | switch (node->u.unary.type) { | |
312 | case AST_UNARY_UNKNOWN: | |
313 | default: | |
314 | fprintf(stderr, "[error] Unknown unary node type in %s\n", | |
315 | __func__); | |
316 | return -EINVAL; | |
317 | case AST_UNARY_PLUS: | |
318 | /* Nothing to do. */ | |
319 | return 0; | |
320 | case AST_UNARY_MINUS: | |
321 | insn.op = FILTER_OP_UNARY_MINUS; | |
953192ba MD |
322 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
323 | case AST_UNARY_NOT: | |
324 | insn.op = FILTER_OP_UNARY_NOT; | |
953192ba MD |
325 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); |
326 | } | |
327 | } | |
328 | ||
329 | /* | |
330 | * Binary comparator nesting is disallowed. This allows fitting into | |
331 | * only 2 registers. | |
332 | */ | |
333 | static | |
334 | int visit_node_binary(struct filter_parser_ctx *ctx, struct ir_op *node) | |
335 | { | |
336 | int ret; | |
337 | struct binary_op insn; | |
338 | ||
339 | /* Visit child */ | |
340 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left); | |
341 | if (ret) | |
342 | return ret; | |
343 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right); | |
344 | if (ret) | |
345 | return ret; | |
346 | ||
347 | switch (node->u.binary.type) { | |
348 | case AST_OP_UNKNOWN: | |
349 | default: | |
350 | fprintf(stderr, "[error] Unknown unary node type in %s\n", | |
351 | __func__); | |
352 | return -EINVAL; | |
353 | ||
354 | case AST_OP_AND: | |
355 | case AST_OP_OR: | |
356 | fprintf(stderr, "[error] Unexpected logical node type in %s\n", | |
357 | __func__); | |
358 | return -EINVAL; | |
359 | ||
360 | case AST_OP_MUL: | |
361 | insn.op = FILTER_OP_MUL; | |
362 | break; | |
363 | case AST_OP_DIV: | |
364 | insn.op = FILTER_OP_DIV; | |
365 | break; | |
366 | case AST_OP_MOD: | |
367 | insn.op = FILTER_OP_MOD; | |
368 | break; | |
369 | case AST_OP_PLUS: | |
370 | insn.op = FILTER_OP_PLUS; | |
371 | break; | |
372 | case AST_OP_MINUS: | |
373 | insn.op = FILTER_OP_MINUS; | |
374 | break; | |
375 | case AST_OP_RSHIFT: | |
376 | insn.op = FILTER_OP_RSHIFT; | |
377 | break; | |
378 | case AST_OP_LSHIFT: | |
379 | insn.op = FILTER_OP_LSHIFT; | |
380 | break; | |
381 | case AST_OP_BIN_AND: | |
382 | insn.op = FILTER_OP_BIN_AND; | |
383 | break; | |
384 | case AST_OP_BIN_OR: | |
385 | insn.op = FILTER_OP_BIN_OR; | |
386 | break; | |
387 | case AST_OP_BIN_XOR: | |
388 | insn.op = FILTER_OP_BIN_XOR; | |
389 | break; | |
390 | ||
391 | case AST_OP_EQ: | |
392 | insn.op = FILTER_OP_EQ; | |
393 | break; | |
394 | case AST_OP_NE: | |
395 | insn.op = FILTER_OP_NE; | |
396 | break; | |
397 | case AST_OP_GT: | |
398 | insn.op = FILTER_OP_GT; | |
399 | break; | |
400 | case AST_OP_LT: | |
401 | insn.op = FILTER_OP_LT; | |
402 | break; | |
403 | case AST_OP_GE: | |
404 | insn.op = FILTER_OP_GE; | |
405 | break; | |
406 | case AST_OP_LE: | |
407 | insn.op = FILTER_OP_LE; | |
408 | break; | |
409 | } | |
410 | return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn)); | |
411 | } | |
412 | ||
8cf9540a MD |
413 | /* |
414 | * A logical op always return a s64 (1 or 0). | |
415 | */ | |
953192ba MD |
416 | static |
417 | int visit_node_logical(struct filter_parser_ctx *ctx, struct ir_op *node) | |
418 | { | |
419 | int ret; | |
420 | struct logical_op insn; | |
421 | uint16_t skip_offset_loc; | |
422 | uint16_t target_loc; | |
423 | ||
424 | /* Visit left child */ | |
425 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.left); | |
426 | if (ret) | |
427 | return ret; | |
8cf9540a | 428 | /* Cast to s64 if float or field ref */ |
586dc72f MD |
429 | if ((node->u.binary.left->data_type == IR_DATA_FIELD_REF |
430 | || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF) | |
8cf9540a MD |
431 | || node->u.binary.left->data_type == IR_DATA_FLOAT) { |
432 | struct cast_op cast_insn; | |
433 | ||
586dc72f MD |
434 | if (node->u.binary.left->data_type == IR_DATA_FIELD_REF |
435 | || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF) { | |
29fefef8 MD |
436 | cast_insn.op = FILTER_OP_CAST_TO_S64; |
437 | } else { | |
438 | cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64; | |
439 | } | |
8cf9540a MD |
440 | ret = bytecode_push(&ctx->bytecode, &cast_insn, |
441 | 1, sizeof(cast_insn)); | |
442 | if (ret) | |
443 | return ret; | |
444 | } | |
953192ba MD |
445 | switch (node->u.logical.type) { |
446 | default: | |
447 | fprintf(stderr, "[error] Unknown node type in %s\n", | |
448 | __func__); | |
449 | return -EINVAL; | |
450 | ||
451 | case AST_OP_AND: | |
452 | insn.op = FILTER_OP_AND; | |
453 | break; | |
454 | case AST_OP_OR: | |
455 | insn.op = FILTER_OP_OR; | |
456 | break; | |
457 | } | |
458 | insn.skip_offset = (uint16_t) -1UL; /* Temporary */ | |
459 | ret = bytecode_push_logical(&ctx->bytecode, &insn, 1, sizeof(insn), | |
460 | &skip_offset_loc); | |
461 | if (ret) | |
462 | return ret; | |
463 | /* Visit right child */ | |
464 | ret = recursive_visit_gen_bytecode(ctx, node->u.binary.right); | |
465 | if (ret) | |
466 | return ret; | |
8cf9540a | 467 | /* Cast to s64 if float or field ref */ |
586dc72f MD |
468 | if ((node->u.binary.right->data_type == IR_DATA_FIELD_REF |
469 | || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF) | |
8cf9540a MD |
470 | || node->u.binary.right->data_type == IR_DATA_FLOAT) { |
471 | struct cast_op cast_insn; | |
472 | ||
586dc72f MD |
473 | if (node->u.binary.right->data_type == IR_DATA_FIELD_REF |
474 | || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF) { | |
29fefef8 MD |
475 | cast_insn.op = FILTER_OP_CAST_TO_S64; |
476 | } else { | |
477 | cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64; | |
478 | } | |
8cf9540a MD |
479 | ret = bytecode_push(&ctx->bytecode, &cast_insn, |
480 | 1, sizeof(cast_insn)); | |
481 | if (ret) | |
482 | return ret; | |
483 | } | |
953192ba MD |
484 | /* We now know where the logical op can skip. */ |
485 | target_loc = (uint16_t) bytecode_get_len(&ctx->bytecode->b); | |
486 | ret = bytecode_patch(&ctx->bytecode, | |
487 | &target_loc, /* Offset to jump to */ | |
488 | skip_offset_loc, /* Where to patch */ | |
489 | sizeof(uint16_t)); | |
490 | return ret; | |
491 | } | |
492 | ||
493 | /* | |
494 | * Postorder traversal of the tree. We need the children result before | |
495 | * we can evaluate the parent. | |
496 | */ | |
497 | static | |
498 | int recursive_visit_gen_bytecode(struct filter_parser_ctx *ctx, | |
499 | struct ir_op *node) | |
500 | { | |
501 | switch (node->op) { | |
502 | case IR_OP_UNKNOWN: | |
503 | default: | |
504 | fprintf(stderr, "[error] Unknown node type in %s\n", | |
505 | __func__); | |
506 | return -EINVAL; | |
507 | ||
508 | case IR_OP_ROOT: | |
509 | return visit_node_root(ctx, node); | |
510 | case IR_OP_LOAD: | |
511 | return visit_node_load(ctx, node); | |
512 | case IR_OP_UNARY: | |
513 | return visit_node_unary(ctx, node); | |
514 | case IR_OP_BINARY: | |
515 | return visit_node_binary(ctx, node); | |
516 | case IR_OP_LOGICAL: | |
517 | return visit_node_logical(ctx, node); | |
518 | } | |
519 | } | |
520 | ||
a187da1a | 521 | LTTNG_HIDDEN |
953192ba MD |
522 | void filter_bytecode_free(struct filter_parser_ctx *ctx) |
523 | { | |
7ca1dc6f DG |
524 | if (!ctx) { |
525 | return; | |
526 | } | |
527 | ||
3f0c8837 DG |
528 | if (ctx->bytecode) { |
529 | free(ctx->bytecode); | |
530 | ctx->bytecode = NULL; | |
531 | } | |
532 | ||
533 | if (ctx->bytecode_reloc) { | |
534 | free(ctx->bytecode_reloc); | |
535 | ctx->bytecode_reloc = NULL; | |
536 | } | |
953192ba MD |
537 | } |
538 | ||
a187da1a | 539 | LTTNG_HIDDEN |
953192ba MD |
540 | int filter_visitor_bytecode_generate(struct filter_parser_ctx *ctx) |
541 | { | |
542 | int ret; | |
543 | ||
544 | ret = bytecode_init(&ctx->bytecode); | |
545 | if (ret) | |
546 | return ret; | |
547 | ret = bytecode_init(&ctx->bytecode_reloc); | |
548 | if (ret) | |
549 | goto error; | |
550 | ret = recursive_visit_gen_bytecode(ctx, ctx->ir_root); | |
551 | if (ret) | |
552 | goto error; | |
553 | ||
554 | /* Finally, append symbol table to bytecode */ | |
555 | ctx->bytecode->b.reloc_table_offset = bytecode_get_len(&ctx->bytecode->b); | |
556 | return bytecode_push(&ctx->bytecode, ctx->bytecode_reloc->b.data, | |
557 | 1, bytecode_get_len(&ctx->bytecode_reloc->b)); | |
558 | ||
559 | error: | |
560 | filter_bytecode_free(ctx); | |
561 | return ret; | |
562 | } |